Image data captured by an image sensor or received from other data sources is often processed in an image processing pipeline before further processing or consumption. For example, raw image data may be corrected, filtered, or otherwise modified before being provided to subsequent components such as a video encoder. To perform corrections or enhancements for captured image data, various components, unit stages or modules may be employed.
Such an image processing pipeline may be structured so that corrections or enhancements to the captured image data can be performed in an expedient way without consuming other system resources. Although many image processing algorithms may be performed by executing software programs on a central processing unit (CPU), execution of such programs on the CPU would consume significant bandwidth of the CPU and other peripheral resources as well as increase power consumption. Hence, image processing pipelines are often implemented as a hardware component separate from the CPU and dedicated to perform one or more image processing algorithms.
The image processing pipeline often includes a sensor interface to perform horizontal and vertical scaling of the captured image data for various purposes. Downscaling the captured image data, for example, reduces the size of the image data and the power consumption associated with further processing of the image data in subsequent components of the image processing pipeline. However, the scaling of image data may have an undesirable property of spreading defective pixels from the captured image data across multiple pixels of the scaled image data because a pixel of an unscaled image data may be used for generating multiple pixels in a scaled image data by interpolation.